In 3D integrated circuit (3D-IC), there are two or more layers of active electronic components which are integrated both vertically and horizontally. Through-silicon-via (TSV) is used as the vertical electrical connection which enables a great deal of functionality packed into a small footprint. In this work we solve the signal TSV assignment problem in 3D-IC taking thermal problem into consideration, while only wire length is concerned in the previous work. Firstly, we propose a multilevel node-weight-oriented flow assignment algorithm to reduce wire length and temperature simultaneously. During the evaluation of wire length and temperature result, we use a thermal estimation model to evaluate temperature, where compression storage method with LU decomposition is adopted to improve algorithm efficiency. Moreover, we implement the remove and reassign optimization method which helps further optimize the TSV assignment results. The experimental results show that our algorithm provides better solution with wire length reduction and temperature decrease.